Electrical conductor



UNITED, STATES PATENT OFFI E.

PHILIP HENRY HOLMES, OF GARDINER, MAINE, ASSIGNOR TO THE HOLMESFIBRE-GRAPHITE MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS.

ELECTRICAL CONDUCTOR.

SPECIFICATION forming part of Letters Patent No. 482,177, datedSeptember 6, 1892.

Application filed January 2, 1 8 92.

To all whom it may concern.-

Be it known that I, PHILIP HENRY l-IoLMns, a citizen of the UnitedStates, residing in Gardiner, Kennebec county, Maine, have inventedcertain Improvements in Electrical Conductors, of which the following isa specification.

The object of my invention is to construct an improved electricalconductor, more particularly such as commutator-brushes and arelightpencils.

In the accompanying drawings, Figure l is a perspective View of anarc-light pencilor stick made in accordance with my invention. Fig. 2 isa similar View of a commutatorbrush, also made in accordance with myinvention. Fig. 3 is a diagrammatic sectional plan View illustrating themanner of producing the conductor; and Fig. 4 is a section on the line 12, Fig. 3. g

In making my improved conductor I prefer to make-it of the compositionset forth in the application filed by me on June 2, 1891, Serial No.394,887, in which plumbagoin a finelydivided state is combined withfiber and compressed and united by a suitable binder.

The main feature of my present invention consists in so making theconductor that it 'will be stratified or laminated and the strata willbe disposed in planes parallel with the direction of flow of theelectrical current through the conductor (if it may be so expressed)when. the latter is used in an electric circuit. This I do by making aplastic mass, preferably of plumbago, fiber, and water, and add theretoa suitable granular mineral substance, such as gypsum, and afterthoroughly mixing the compound I place it in a mold A, Fig. 3, having inthe bottom, top, or side (as the case may be) a series of smallpassages. Then upon forcinga plunger 1) into the mold under heavypressure the Water or other fluid in the compoundwill be forced to passout through the small openings a towaste, the fiber and the granularmaterial acting as a filter and preventing the escape of the plumbago,while the particles of fiber and plumbago will be turned in thedirection of flow of the water, and will thereby be caused to lieparallel or substantially parallel with the face of the enial No.416,868. (No model.)

plunger. When the material is removed from the mold, it is dried, so asto completely rid the massof any moisture, and is then submerged in adrying-oil, which when it hardens, preferably under heat, binds the masstogether.

The oil treatment may be omitted in cases where the strengthening andtoughening of the composition resulting from such treatment are notessential; or, on the other hand, when the oil treatment is used thefiber may in some cases be omitted from the compound.

In making commutator-brushes or arc-light pencils the pressure isexerted in a direction transversely to the length of the desiredarticle, so that the strata, lying in planes parallel with the face ofthe plunger, will, when the commutator is shaped as shown in Fig. 2, orthe arc-light pencil is shaped as shown in Fig. 4, lie in planesparallel with the direction of flow of an electric current through theconductor when the latter is in use. I have found that a conductor withthe strata so arranged offers less resistance to the electric currentthan one in which the strata are in planes transverse to the flow of thecurrent.

Another advantage gained by the disposal of the strata in the mannerabove described is that in commutator-brushes the strata are presentedon end to the commutator, so that the commutator-brush does not wearaway so fast as it would if the strata were arranged in a differentmanner.

I claim as my invention- 1. An electric conductor composed of particlesof plumbago disposed in strata which lie in planes parallel with thedirection of the current.

2. An electric conductor composed of particles of electric-conductingcarbon and divided fiber disposed in strata which lie in planes parallelwith the direction of the current.

3. An electric conductor composed of particles of electric-conductingcarbon united by an oil-binder and disposed in strata which lie inplanes parallel with the direction of the current.

4. An electric commutator-brush composed of particles ofconducting-carbon, such as plumbago, disposed in strata, which lie inplanes parallel with the direction of the current, and are thuspresentedon end to the 5 commutator when the brush is in use,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

PHILIP HENRY HOLMES.

Witnesses HENRY I-IoWsoN, EUGENE ELTERIOH.

